﻿Shader "Dou/UIRichText"
{
    Properties
    {
        [PerRendererData] _MainTex ("Sprite Texture", 2D) = "white" {}
        _Color ("Tint", Color) = (1,1,1,1)

        _StencilComp ("Stencil Comparison", Float) = 8
        _Stencil ("Stencil ID", Float) = 0
        _StencilOp ("Stencil Operation", Float) = 0
        _StencilWriteMask ("Stencil Write Mask", Float) = 255
        _StencilReadMask ("Stencil Read Mask", Float) = 255

        _ColorMask ("Color Mask", Float) = 15

        [Toggle(UNITY_UI_ALPHACLIP)] _UseUIAlphaClip ("Use Alpha Clip", Float) = 0

        _SpriteSheetTex ("Sprite Sheet Texture", 2D) = "white" {}
        _SpriteSize ("Sprite Size", float) = 0.125
        _Column ("Column",float) = 8
        _Speed("Animation Speed",Range(0,10)) = 3
    }

    SubShader
    {
        Tags
        {
            "Queue"="Transparent"
            "IgnoreProjector"="True"
            "RenderType"="Transparent"
            "PreviewType"="Plane"
            "CanUseSpriteAtlas"="True"
        }

        Stencil
        {
            Ref [_Stencil]
            Comp [_StencilComp]
            Pass [_StencilOp]
            ReadMask [_StencilReadMask]
            WriteMask [_StencilWriteMask]
        }

        Cull Off
        Lighting Off
        ZWrite Off
        ZTest [unity_GUIZTestMode]
        Blend SrcAlpha OneMinusSrcAlpha
        ColorMask [_ColorMask]

        Pass
        {
            Name "Default"
        CGPROGRAM
            #pragma vertex vert
            #pragma fragment frag
            #pragma target 2.0

            #include "UnityCG.cginc"
            #include "UnityUI.cginc"

            #pragma multi_compile_local _ UNITY_UI_CLIP_RECT
            #pragma multi_compile_local _ UNITY_UI_ALPHACLIP

            struct appdata_t
            {
                float4 vertex   : POSITION;
                float4 color    : COLOR;
                float2 texcoord : TEXCOORD0;
                UNITY_VERTEX_INPUT_INSTANCE_ID
            };

            struct v2f
            {
                float4 vertex   : SV_POSITION;
                fixed4 color    : COLOR;
                float2 texcoord  : TEXCOORD0;
                float4 worldPosition : TEXCOORD1;
                float4  mask : TEXCOORD2;
                float2 texcoord3 : TEXCOORD3;
                UNITY_VERTEX_OUTPUT_STEREO
            };

            sampler2D _MainTex;
            fixed4 _Color;
            fixed4 _TextureSampleAdd;
            float4 _ClipRect;
            float4 _MainTex_ST;
            float _UIMaskSoftnessX;
            float _UIMaskSoftnessY;
            int _UIVertexColorAlwaysGammaSpace;

            sampler2D _SpriteSheetTex;
            float _SpriteSize;
            float _Column;
            float _Speed;

    //         v2f vert(appdata_t IN)
    //         {
    //             v2f OUT;
    //             OUT.vertex = UnityObjectToClipPos(float4(IN.vertex.x, IN.vertex.y, IN.vertex.z, 1.0));
    //
    //             OUT.texcoord3 = half2(floor(IN.texcoord.x * 0.1), floor(IN.texcoord.y * 0.1));
    //             OUT.texcoord = IN.texcoord - OUT.texcoord3 * 10;
    //
    //             #ifdef UNITY_HALF_TEXEL_OFFSET
				// OUT.vertex.xy += (_ScreenParams.zw-1.0) * float2(-1,1) * OUT.vertex.w;
    //             #endif
    //
    //             OUT.color = IN.color * _Color;
    //             return OUT;
    //         }

            v2f vert(appdata_t v)
            {
                v2f OUT;
                UNITY_SETUP_INSTANCE_ID(v);
                UNITY_INITIALIZE_VERTEX_OUTPUT_STEREO(OUT);
                float4 vPosition = UnityObjectToClipPos(v.vertex);
                OUT.worldPosition = v.vertex;
                OUT.vertex = vPosition;

                float2 pixelSize = vPosition.w;
                pixelSize /= float2(1, 1) * abs(mul((float2x2)UNITY_MATRIX_P, _ScreenParams.xy));

                float4 clampedRect = clamp(_ClipRect, -2e10, 2e10);
                float2 maskUV = (v.vertex.xy - clampedRect.xy) / (clampedRect.zw - clampedRect.xy);
                OUT.texcoord = TRANSFORM_TEX(v.texcoord.xy, _MainTex);
                OUT.mask = float4(v.vertex.xy * 2 - clampedRect.xy - clampedRect.zw, 0.25 / (0.25 * half2(_UIMaskSoftnessX, _UIMaskSoftnessY) + abs(pixelSize.xy)));

                if (_UIVertexColorAlwaysGammaSpace)
                {
                    if(!IsGammaSpace())
                    {
                        v.color.rgb = UIGammaToLinear(v.color.rgb);
                    }
                }

                OUT.color = v.color * _Color;
                return OUT;
            }
        
    //         fixed4 frag(v2f i) : SV_Target
    //         {
    //             fixed4 color;
    //             if (i.texcoord3.y > 0)
    //             {
    //                 // it's an emoji
    //                 // compute current frame index of emoji
    //                 float index = floor((_Time.x * _Speed * 50) % i.texcoord3.y);
    //                 // compute real uv xy
    //                 float offsetU = fmod((i.texcoord3.x + index), _Column);
    //                 float offsetV = floor((i.texcoord3.x + index) / _Column);
    //                 float2 originUV = float2(offsetU, offsetV) * _SpriteSize;
    //                 float2 uv = originUV + i.texcoord * _SpriteSize;
    //                 uv = uv - float2(0.001, 0.001); // 0.001 用来矫正误差的，防止表情周边有表情图集中其他表情的黑边
    //
    //                 color = tex2D(_SpriteSheetTex, uv);
    //             }
    //             else
    //             {
    //                 // it's a text, and render it as normal ugui text
    //                 color = (tex2D(_MainTex, i.texcoord) + _TextureSampleAdd) * i.color;
    //             }
    //
    //             #ifdef UNITY_UI_ALPHACLIP
				// clip (color.a - 0.001);
    //             #endif
    //
    //             return color;
    //         }

            fixed4 frag(v2f IN) : SV_Target
            {
                //Round up the alpha color coming from the interpolator (to 1.0/256.0 steps)
                //The incoming alpha could have numerical instability, which makes it very sensible to
                //HDR color transparency blend, when it blends with the world's texture.
                const half alphaPrecision = half(0xff);
                const half invAlphaPrecision = half(1.0/alphaPrecision);
                IN.color.a = round(IN.color.a * alphaPrecision)*invAlphaPrecision;

                half4 color = IN.color * (tex2D(_MainTex, IN.texcoord) + _TextureSampleAdd);

                #ifdef UNITY_UI_CLIP_RECT
                half2 m = saturate((_ClipRect.zw - _ClipRect.xy - abs(IN.mask.xy)) * IN.mask.zw);
                color.a *= m.x * m.y;
                #endif

                #ifdef UNITY_UI_ALPHACLIP
                clip (color.a - 0.001);
                #endif

                color.rgb *= color.a;

                return color;
            }
        
        ENDCG
        }
    }
}
